A liquid crystal display device of ADS mode (Advanced Super Dimension Switch mode) has advantages of wide viewing angle, high transmittance and high definition, thus the ADS mode becomes an important mode of the liquid crystal display device.
As shown in FIG. 1, in an array substrate of the ADS mode, a first transparent electrode 111 of plate-shape, a gate 21 and a gate line 22 of a thin film transistor are provided on a substrate base 9, and a gate insulation layer 31 covers the first transparent electrode 111, the gate 21 and the gate line 22. A semiconductor layer 41 is provided above the gate 21, the semiconductor layer 41, an ohmic contact layer and a transition layer constitute an active region of the thin film transistor. A passivation layer 5 and a planarization layer 6 sequentially cover the semiconductor layer 41 and the gate insulation layer 31. A data line Data and a second transparent electrode 121 are provided on the planarization layer 6. The data line Data and the second transparent electrode 121 are electrically connected to a source 71 and a drain 72 of the thin film transistor, respectively. The second transparent electrode 121 is a slit-shaped electrode, and is provided above the first transparent electrode 111. It should be understood that, although a case in which the second transparent electrode 121 is a pixel electrode and the first transparent electrode 111 is a common electrode is taken as an example, but if the first transparent electrode 111 is the pixel electrode (i.e., is electrically connected to the drain 72), the second transparent electrode 121 may be the common electrode.
As shown in FIG. 1, in the array substrate of the ADS mode in prior art, the gate 21, the gate line 22, the semiconductor layer 41, the first transparent electrode 111, the source 71, the drain 72 and the second transparent electrode 121 are needed to be fabricated in different patterning processes, respectively, that is, photolithography is required to be performed at least six times so as to fabricate those structures. Therefore, the fabricating process is complex.
Meanwhile, the gate insulation layer 31 covers the whole substrate base 9, that is, the gate insulation layer 31 is also provided between the first transparent electrode 111 and the second transparent electrode 121, which increases a distance between the two electrodes and reduces an intensity of electric field and a capacitance, so that driving effect is deteriorated. On the other hand, the gate insulation layer 31 also affects light transmission, so that light transmittance of the array substrate is reduced.